The invention relates to a cruise control system for motor vehicles for controlling the speed to a preset desired speed.
Cruise control systems permit driving at a desirable speed adjustable by the driver without requiring the driver to continuously define the speed by way of the accelerator pedal. These cruise control systems are suitable mainly for driving on expressways having a low traffic density because constant-speed driving is often desirable there.
Motor vehicles with cruise control systems have been known for a long time. Most currently available cruise control systems control the speed of the motor vehicle to a preset desired speed. In addition to these speed control systems, cruise control systems having a range control system are also obtainable from a few manufacturers. With respect to the principle, the generally known cruise control system, which maintains a certain preset desired speed, is expanded in this case by an additional ranging function, so that the use of such a “range-related” cruise control also becomes possible in dense expressway and road traffic. This so-called “range-related” cruise control system maintains the preset desired speed when its own traffic lane is free. When a range sensor system mounted on the motor vehicle, which, in particular, may operate on a radar basis, recognizes in its own traffic lane a target object or (motor) vehicle driving ahead if it, its own speed will be adapted to the speed of the motor vehicle driving ahead, for example, by causing a suitable braking torque. In some cases, such systems are capable of controlling a following vehicle to a stop.
In principle, cruise control systems can be switched on and off by use of a first operating unit mounted on the steering wheel or dashboard or by use of a lever arranged in the proximity of the steering wheel. As a rule, the desired speed is also preset by way of a corresponding second operating unit, in which case, by means of the actuation, either the current speed is set as the desired speed by actuating a so-called set key, or an already stored (old) desired speed is set as a new desired speed by actuating a so-called resume key. In this case, a separate operating element for each function or adjustment is provided within the operating units.
Furthermore, the speed control of cruise control systems further developed in such a manner can be interrupted as a result of certain driving or driver's maneuvers, so that the cruise control system is basically still switched on but the speed control is currently not implemented. An interruption of the speed control takes place, for example, when the driver actuates the brake pedal or the hand brake, or because of an automatic directional control intervention. Cruise control systems further developed in this manner are often difficult to operate for persons who do not regularly use the cruise control system because, as a result of the numerous operating elements, the selection of functions appears to be confusing.
As an alternative to currently available cruise control systems, DE 2829894 A1 also discloses a system for automatically controlling the speed of the motor vehicle to a preset desired speed, wherein the desired speed is not preset by a separate operating element, but rather by actuating the accelerator pedal or the brake pedal. In this case, when the driving speed desired by him has been reached, the person steering the vehicle can continue to drive at the current speed by removing his foot from the just actuated pedal (accelerator pedal or brake pedal). An interruption of the cruise control does not seem to be possible.
It is an object of the invention to provide a cruise control system that can be operated by the driver in a simple and intuitive manner.
This object is achieved by a cruise control system for a motor vehicle for controlling the vehicle speed to a preset desired speed. An operating unit is provided for switching the cruise control on and off. An accelerator pedal is provided for activating the cruise control and for presetting the desired speed. A brake pedal interrupts the active cruise control. Advantageous further developments are described herein.
In a simplest embodiment, the cruise control system according to the invention includes only the following three operating elements by whose actuation all adjustments for controlling the speed can be carried out: (a) an operating unit for switching the cruise control on and off, (b) an accelerator pedal, which is present anyhow, for activating the cruise control and for presetting the desired speed, and (c) a brake pedal, which is present anyhow, for interrupting the active cruise control.
This cruise control system therefore has the advantages of the known cruise control systems without their disadvantages, specifically the disadvantages of having a complicated operation. As a result of this invention, the driver can carry out an extremely simple and intuitive operation of the essential adjustments for controlling the speed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.